Duplicate Emails Sent by Oracle Alert

Hello Team,

I have created a APPROVAL alert on PO_REQUISITION_HEADERS_ALL; although, porhall.ROWID=:ROWID and Suppress Duplicates (flag ticked)

SELECT

       to_char(sysdate,'DD/MON/RRRR HH24:MI:SS'),

       porhall.segment1||', '||porlall.line_num,

       porhall.requisition_header_id,

       porlall.requisition_line_id   ,

       oun_hrorgu.name,

       prep_perallpf.first_name

       ||' '

       ||prep_perallpf.last_name,

       dl_hrorgu.name,

       porlall.item_id,

       porlall.item_description,

       porlall.unit_meas_lookup_code,

       porlall.quantity,

       porlall.need_by_date,

       prep_perallpf.email_address,

       porlall.SUGGESTED_BUYER_ID,

       buy_perallpf.first_name

       ||' '

       ||buy_perallpf.last_name,

       buy_perallpf.email_address,